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#13471. Permutation

Statistiques

Given $n$ and $P$, let

$$ f_n = \left(\sum_{p\text{ is a permutation of length }n} [\exists i \in [1,n] , p_i = i][\exists i \in [1,n] , p_i = n - i + 1]\right) \bmod\ P $$

You need to find the value of $\bigoplus_{i=1}^n f_i$.

Input

A single line containing two integers $n$ and $P$.

Output

A single line containing an integer representing the answer.

Examples

Input 1

2 100000

Output 1

1

Note 1

For $n=1$, the permutation $(1)$ satisfies both conditions, so $f_1 = 1$.

For $n=2$, the permutations $(1,2)$ and $(2,1)$ each fail to satisfy one of the conditions, so $f_2 = 0$.

Therefore, the answer is $1\oplus 0 = 1$.

Subtasks

For $100\%$ of the data, $1 \leq n \leq 10^7$ and $n + 1 \leq P \leq 10^9$.

Test Case ID $n \leq$ $P$
$1$ $18$ No special restrictions
$2$ $60$
$3$ $300$
$4$ $1000$ $=998244353$
$5$ $5000$
$6$ $3 \times 10^4$
$7$ $10^5$
$8$ $3 \times 10^5$
$9$ $5 \times 10^5$
$10$ $1000$ Is a prime number
$11$ $10^4$
$12$ $10^5$
$13$ $10^6$
$14$ $10^7$
$15$ $5000$ No special restrictions
$16$ $3 \times 10^4$
$17$ $10^5$
$18$ $5 \times 10^5$
$19$ $2 \times 10^6$
$20$ $10^7$

Editorials

IDTypeStatusTitlePosted ByLast UpdatedActions
#847EditorialOpen题解alpha10222026-01-28 02:20:46View

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